The present invention relates, in general, to telephone networks and, more specifically, to a system that passively monitors telephone services and traffic in a telephone network and reports the same to a user.
Modem telephone networks require a signaling system for management of a variety of call setup and control functions, such as call routing and billing. One version of a signaling system is a Common Channel Signaling System No. 7, referred to as SS7. The SS7 follows an international standard defined by the International Telecommunications Union (ITU), and its variants such as those defined by the American National Standards Institute (ANSI) and Bell Communications Research (Bellcore).
The telephone network typically includes a plurality of offices through which telephone calls may be routed, each office being owned by a telephone company that participates in the network. The telephone company may be a Regional Bell Operating Company (RBOC) of an Independent Telephone Company (ITC), for example. Each office includes a signaling service point (SSP) for formulating a message signaling unit (MSU). An MSU may include a request for data pertinent to a particular call or a message for setting up a call. In the terminology used in the SS7 system, these offices are referred to as having SP (signaling point) capability.
Within each RBOC or ITC, the SS7 includes one or more signal transfer points (STPs). Each STP is essentially a specialized packet switch for receiving and transmitting digital data using packet switch technology. Each office with a SSP is coupled to an STP. Typically, several SSPs may be coupled to a single STP. In addition, communications between different telephone companies may be between their respective STPs.
In an SS7 system, an SSP may be coupled to an STP by way of a digital link, referred to as an A-link. Furthermore, an STP may be coupled to another STP by way of a different digital link, referred to as a B-link. A B-link typically includes a data transfer rate of 56 kbps.
A conventional telephone network, designated 10, is shown in FIG. 1. As shown, ITC 12 and ITC 14, respectively including SSP 24 and SSP 26 are coupled via A-links to a hub-STP 20. RBOC 16 and RBOC 18, respectively including STP 28 and STP 30 are coupled to hub-STP 20 via B-links. In the network shown, STP 20 is referred to as a hub-STP, because of its central position in the network architecture. The primary function of hub-STP 20 is to route SS7 messages from one SSP to another, for example, between SSP 24 and SSP 26 or between STP 28 and STP 30.
These messages, termed MSUs, include queries, responses to queries, and trunk signaling messages. By way of example, an MSU may be a message requesting information as to whether a credit card number was valid. A response may be the requested validation information. A trunk signaling message may be a message to set up a voice circuit in the existing network. Each time that an MSU is received by hub-STP 20, a copy of the MSU is also received by billing system 22. The received MSU data is processed by the billing system to produce invoices, bills and reports, as further described in U.S. Pat. No. 5,008,929 issued Apr. 16, 1991 to Olsen et al.
Additional description of the SS7 system and various MSU types is provided in U.S. Pat. No. 5,008,929, which is incorporated herein by reference.
In the network shown in FIG. 1, billing system 22 monitors MSU messages received from hub-STP 20. Billing system 22 depends on hub-STP 20 to reformat the MSU messages from the other SSPs and STPs and then transmit the messages to the billing system. Reconstructing the messages as they appear across multiple links in a typical SS7 distributed network is laborious and time consuming.
Billing system 22 processes the MSUs to produce usage data that indicates service recipients and service providers. The service recipient is the telephone company that own the SSP that formulated the MSU, and the service provider is the telephone company that provided the call data for the MSU, or that transported the MSU. The usage data may then be used to produce invoice data for assigning costs among the telephone companies. Independent verification of the accuracy of the usage data and assigned costs by a telephone company is also laborious and time consuming.
The deficiency of the conventional system to consolidate and correlate data across multiple links of a typical distributed SS7 network show that a need still exists for an improved system. In addition, a need exists for an independent system to verify the reliability and accuracy of usage data provided by a conventional system, such as billing system 22.
To meet this and other needs, and in view of its purposes, the present invention provides a mediation system for a telephone network. One embodiment, includes a telephone network having a plurality of signaling service points (SSPs) communicating message signaling unit (MSU) data with a plurality of signal transfer points (STPs). The MSU data is routed on data links connecting the plurality of SSPs and STPs. The mediation system includes a probe and a mediator. The probe is connected to at least one of the data links for intercepting the MSU data routed on the one data link, and the mediator is coupled to the probe for collecting the MSU data and generating a call detail record (CDR). In another embodiment, the probe is connected to a plurality of data links, wherein the plurality of data links route MSU data to one of the STPs. The probe intercepts either A-link data and/or E-link data on the data links. The probe includes a filter for filtering MSU data. In another embodiment, the mediator includes a correlator for sorting the MSU data into queues, each of the queues store MSU data from a single data link. The correlator includes a data router for routing MSU data from a data link to a predetermined queue.
It is understood that the foregoing general description and the following detailed description are exemplary, but are not restrictive, of the invention.